How to Replace Boards on Your Wood Deck

This is Part 3 of 9 in our Series on Restoring Wood Decks and Building New Wood Decks. Navigate to the first article: Restoring a Wood Deck

In the first article, you checked your deck for rot. But if you found some, you can't just send your deck out for a month of rehab in a clinic. You need to deal with it yourself. And that can range from replacing just a board here and there to replacing the whole deck. Here is a look at some simple repairs.

Replacing a Few Boards

Perhaps only a small portion of some boards has rotted (for instance, a section under a planter), and all you need to do is cut off the bad and reuse the good. Re-using the good part of the old boards will reduce the amount of wood you need to purchase. It also reduces the amount of new, unweathered wood in your deck, which would contrast unpleasantly with the older weathered deck.

You need to be careful in removing the bad boards if you want to salvage the good section for reuse--the wood will split easily. If you can get under the deck, the easy solution is to pound upwards with a block of wood set against the underside of the board you want to remove, driving the block up with a heavy hammer or small sledge at the point it is nailed to the joist. The block of wood will keep your board from splitting.

Deck Board Removal: Pulling and Popping

If you can't get under your deck, you can use a cat-paw nail puller. Pull the nails in the rotted area and see if lifting up on the board won't pop the rest of the nails loose from the joist on down the length of the board.

It is likely the rotted part of the board will simply break off, without loosening nails along the remaining good wood. If this happens, you may have enough room to run a pry bar along the underside of the board to pry it up from the next joist, though you need to take care not to crack the board with the leverage of the pry bar.

As you lift the board, you also may be lifting the nails up out of the joist (otherwise, the nails are staying firm in the joist and the nail heads are pulling through your board). If the nails have lifted with the board an eighth of an inch or more, tap your board back down against the joist and see if the nail heads remain up above the board. If so, the best thing to do is to pull them out. Just make certain to put a protector board between your nail puller and the deck board to keep the puller from marring the wood.

You may find that you are having a difficult time pulling the boards without splitting them. That's the way it is with an old house--old wood sometimes gets a little cranky.

You probably will have some rusty nails remain in the joist when you pull up the board. Pull them from the wood as you go to eliminate the possibility of cutting or puncturing yourself on them.

Once the boards are up, you can start replacing the bad sections. If you are nailing the old boards, you should use the same nail holes, using nails a size larger than what was used before. You might want to install any new boards in an inconspicuous place or in the area that had rotted.

That takes care of simple board replacement. But your joists also may be bad. Next we will look at joist repair.

Next article: Repair Deck Joists. Addressing wood rot in deck joists.